Effectiveness of Robot-assisted Adrenalectomy for a Giant Adrenal Hemangioma: A Case Report

Discussion

We experienced a case of a giant adrenal tumor, which was suspected to be an adrenal carcinoma and was treated safely with robot-assisted adrenalectomy. Pathological examination revealed that the tumor was hemangioma.

Adrenal hemangiomas are benign tumors arising from endothelial cells lining blood vessels. However, they are often difficult to distinguish from malignant tumors (1, 2). The age of onset is usually 50-70 years, with a male-to-female ratio of 2:1. Although adrenal hemangiomas are usually asymptomatic and are incidentally detected on imaging, large or ruptured adrenal hemangiomas may cause unilateral abdominal pain (3). In our case, an 11-cm adrenal tumor was found on computed tomography (CT) performed for evaluation of left-sided abdominal pain. Adrenal hemangiomas have been reported to present with characteristic features. CT scans of adrenal tumors typically reveal a characteristic irregular peripheral enhancement with progression to the center of the tumor and calcification within the tumor, appearing as a speckled pattern throughout the entire mass (4). In our case, CT showed an uneven distribution and calcification of the tumor. However, 30% of adrenal carcinomas present with calcifications on CT and require differentiation (5). Surgical resection is recommended for adrenal tumors >4 cm in size due to the possibility of spontaneous rupture and malignancy (6). Therefore, we performed a robot-assisted adrenalectomy. The surgical approaches include open surgery, laparoscopy, and robotic surgery. Although open surgery was previously performed in cases of large adrenal tumors or suspected malignancy to avoid tumor rupture or dissemination, Zografos et al. reported that outcomes following laparoscopic surgery did not significantly differ from those following open surgery regarding perioperative complications. Moreover, laparoscopic surgery was associated with a shorter length of hospital stays, less intraoperative blood loss, and less postoperative pain than open surgery (7). Davey et al. also reported that laparoscopic surgery has a lower postoperative complication rate than open surgery (8). Additionally, Jalabneh et al. recommended laparoscopic surgery regardless of malignancy or tumor size (9). In contrast, Germain et al. reported that the laparoscopic approach for giant or suspected malignant adrenal tumors is contraindicated in situations where the risk of tumor rupture or incomplete tumor resection is high, and they described the upper limit of tumor size as 8 cm. Currently, there is no established method to diagnose adrenal hemangiomas before surgery, and a definitive diagnosis is made based on postoperative pathological findings. Therefore, the ability to safely perform minimally invasive surgery for giant adrenal tumors is currently under investigation.

Recently, robotic surgery for giant adrenal tumors has been performed in only a few cases. Agcaoglu et al. reported that for adrenal tumors >5 cm, robotic surgery requires less time and has a lower conversion rate to open surgery than laparoscopy (10). A prospective study comparing perioperative outcomes in 50 patients who underwent robotic adrenalectomy and 59 patients who underwent laparoscopic surgery found that robotic surgery had less impact on operative time when the tumor size was greater than 5.5 cm (11). Changwei et al. reported less intraoperative blood loss and shorter hospital stay with robotic surgery than with laparoscopic surgery (12). Lijian et al. reported that robotic surgery has been reported to be useful for obese patients and for adrenal tumors larger than 5 cm (13). Some studies have also reported that bleeding from the tumor, paranephric arteriovenous hemorrhage, and adhesions to the surrounding area are the main reasons for conversion from laparoscopic surgery to open surgery and that these factors can be improved by the 3-D vision of the robot (10, 14). Ragavan et al. reported that robotic surgery for larger tumors has a lower risk of adrenal tumor rupture than laparoscopic surgery because there are fewer restrictions on motion (15). In contrast, Francis et al. reported that postoperative morbidity and mortality rates were similar between the laparoscopic and robotic approaches (16). Another drawback of robotic surgery is its high cost. Brunaud et al. reported that the cost of robotic surgery was 2.3 times more than that of laparoscopic surgery in their center. Based on these findings, robotic surgery may be useful for adrenal tumors, especially large tumors. A PubMed search revealed eight cases of giant adrenal tumors measuring >8 cm that were treated with robot-assisted surgery (Table I) (17-23). The patients’ age ranged between 16-73 years and included six males. Tumor size ranged from 8.3 to 16 cm in diameter. The patient in case 4 underwent robot-assisted partial adrenalectomy because the adrenal tumor exhibited characteristics of a benign tumor on preoperative imaging (20). All patients except the patient in case 4 underwent robot-assisted adrenalectomy because malignancy could not be ruled out by preoperative findings. All cases were performed with no perioperative complications. Adrenal carcinoma was diagnosed in two of the eight cases, and our case was the first case of an adrenal hemangioma measuring >8 cm in size treated with robotic surgery with no complications. Although the preoperative diagnosis of adrenal hemangioma is difficult and the risk of intraoperative rupture is higher than that of other adrenal tumors (24), robot-assisted adrenalectomy can be safely performed.